Related papers: Loop Calculations and OZI Rule
In this paper, we calculate the next-to-leading-order (NLO) twist-3 contribution to the form factors of $B \to \pi$ transitions by employing the $k_{T}$ factorization theorem. All the infrared divergences regulated by the logarithms…
A model calculation for pion production in nucleon-nucleon collisions is presented. Direct production, pion rescattering and contributions from pair diagrams are taken into account. The amplitudes for the elementary processes are based on…
We determine the full structure of the leading (double-pole) divergences of O(p^6) in the meson sector of chiral perturbation theory. The field theoretic basis for this calculation is described. We then use an extension of this result to…
Two schemes are presented that mitigate the effect of errors and decoherence in short depth quantum circuits. The size of the circuits for which these techniques can be applied is limited by the rate at which the errors in the computation…
The energy dependence of the cross sections of $p\bar p$, $n\bar n$, and meson production in $e^+e^-$ annihilation in the vicinity of the $p\bar p$ and $n\bar n$ thresholds is studied. The proton-neutron mass difference and the $p\bar p$…
We discuss the puzzling experimental results on baryon-antibaryon production in e+e- annihilation close to the threshold, in particular the fact that sigma(e+e- --> nbar n) is somewhat greater than sigma(e+e- --> pbar p). We discuss an…
The study of the process phi-->gamma K0 bar(K0) is calculated to be 5.10^(-8) in a scheme which takes into account the different isospin channels involved, I=0,1 with the resonant, f_0(980), a_0(980), and non resonant contributions.
Quantum Phase Estimation (QPE) is a cornerstone algorithm for fault-tolerant quantum computation, especially for electronic structure calculations of chemical systems. To accommodate the diverse characteristics of quantum chemical systems,…
In this paper, we calculate the branching ratios and CP violating asymmetries of the five $\bar{B}^0_s \to (\pi^0\eta^{(*)},\eta^{(*)}\eta^{(*)})$ decays, by employing the perturbative QCD (pQCD) factorization approach and with the…
The partition function of the O(n) loop model on the honeycomb lattice is mapped to that of the O(n) loop model on the 3-12 lattice. Both models share the same operator content and thus critical exponents. The critical points are related…
For Z -> b bbar, we calculate all the two-loop top dependent Feynman graphs, which have mixed QCD and electroweak contributions that are not factorizable. For evaluating the graphs, without resorting to a mass expansion, we apply a two-loop…
CP violation in charm decay was observed in the decays $D^0\rightarrow P^{\pm}P^{\mp}$ of a $D^0$ meson to two pseudoscalars. When interpreted within the SM, the results imply that the ratio of the relevant rescattering amplitudes has a…
The implication of the many time formalism for the process $\Phi$ $\rightarrow$ $K^0 \ + {\bar K}^0$ was discussed in a recent letter of B. Kayser and L. Stodolsky who predicted a small correction ($\sim\ 5 \%$) to the usually predicted…
In this paper, we study the structure around the $p\bar{p}$ threshold that appears in $\eta'\pi^+\pi^-$, $3(\pi^+\pi^-)$ and $K_S^0K_S^0\eta$ invariant mass spectra in the processes of relevant $J/\psi$ radiative decays. The $N\bar{N}$…
We present our calculation of the two-loop corrections of ${\cal O}(\alpha_t^2)$ to the neutral Higgs boson masses of the CP-violating Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM). The calculation is performed in…
The experimental observation indicates that the branching ratio of $\psi'\to \rho\pi$ is very small while the $\rho-\pi$ channel is a main one in $J/\psi$ decays. To understand the puzzle, various interpretations have been proposed.…
Using the analysis of ChPT to two loops, we perform an error analysis of the threshold and low energy parameters, based on the uncertainties for the one loop low energy parameters and the resonance saturation mechanism. Different sets of…
The recently proposed hard-pion chiral perturbation theory predicts that the leading chiral logarithms factorize with respect to the energy dependence in the chiral limit. This claim has been successfully tested in the pion form factors up…
The two-point functions of the energy-momentum tensor and the Noether current are used to probe the O(3) nonlinear sigma model in an energy range below 10^4 in units of the mass gap $m$. We argue that the form factor approach, with the form…
The theoretical study of cross sections for polarized--target measurements of $ \pi N \to \pi \pi N $ reactions gives evidence that the interplay between the strong contribution from OPE mechanism and the one from isobar exchanges, which is…